Mycoplasma and Ureaplasma contribute to recurrent pregnancy loss, suggests research

Mycoplasma hominis and Ureaplasma urealyticum are genital mycoplasmas that can infect the upper and lower reproductive tract. These organisms are often subclinical and not routinely tested during infertility or miscarriage evaluations. Both Mycoplasma and Ureaplasma have been implicated in adverse pregnancy 3 outcomes such as preterm delivery and miscarriage and infection by mycoplasmas has greater prevalence in patients with recurrent pregnancy loss compared to patients undergoing induced abortion as well as to those without RPL. This study aimed to specifically investigate the prevalence of Mycoplasma hominis and Ureaplasma urealyticum infections via high endocervical cultures in women with RPL and to evaluate treatment outcomes. By adopting a targeted approach to testing for these pathogens, authors aim to improve diagnostic specificity and provide pathogen-specific treatments that may enhance 10 pregnancy outcomes.

It was a Single-center, prospective cohort study from 2005 to 2015 including 1,846 women evaluated at a 15 reproductive medicine clinic. Women who sought treatment for RPL with 2 or more consecutive first trimester pregnancy 19 losses (n=1,583) and 263 infertile controls. A pregnancy loss was included for a patient if it was documented with a serum human chorionic gonadotropin (hCG) or ultrasound.

All patients underwent testing for Mycoplasma and Ureaplasma using high endocervical cultures. Positive cases and partners were treated with a 14-day course of doxycycline, followed by a test-of-cure. Alternative antibiotics were administered if initial therapy failed. Primary outcomes included infection rates of Mycoplasma and Ureaplasma. Secondary outcomes assessed treatment success and subsequent live birth rates in the recurrent pregnancy loss population.

Recurrent pregnancy loss patients had higher infection rates of Mycoplasma (4.2%; RR 10.9, CI 8 1.53–78.7) and Ureaplasma (15.7%; RR 1.59, CI 1.09–2.33) compared to controls (0.1% and 9.89%, respectively). Over 95% achieved negative test-of-cure cultures post-treatment. Live birth rates were significantly higher in successfully treated patients: 78% for Mycoplasma and 76% for Ureaplasma, compared to 64% in culture-negative recurrent pregnancy loss cases (p=0.045 and p=0.002, respectively).

These findings demonstrate increased prevalence of Mycoplasma hominis and Ureaplasma urealyticum within the RPL population, that these infections can be easily treated with antibiotic therapy, and that pregnancy outcomes between RPL patients who were cured from these infections were significantly improved compared to those who initially tested negative. By adopting a targeted approach to testing for these and other specific pathogens combined with a second modality such as CD13+, histology, or hysteroscopy, study aimed to improve diagnostic specificity for patients and provide pathogen-specific treatments to enhance future pregnancy outcomes.

Source: Bishop S, Truong A, Jaslow C, Kutteh W, Recurrent Pregnancy Loss and the Role of Mycoplasma and Ureaplasma: A Prospective Cohort Study with Outcome after Treatment, Fertility and Sterility (2026), doi: https://doi.org/10.1016/j.fertnstert.2025.12.015.